On the Alaska-Canada boundary, 5 mi S of Mount Armour, and 42 mi. NE of Yakutat, St. Elias Mts.
Named by International Boundary Commission (IBC) in 1923 for Sir Lyman Poore Duff, 1865-1948, a junior counsel before International Boundary Commission (IBC) in 1903, and Judge of the Supreme Court of Canada. Born in Canada, he was educated at the University of Toronto and later served as Judge of the Supreme Court of British Columbia and the Supreme Court of Canada. He became Chief Justice in 1933, which position he held until his retirement in 1944.
Art Lewis Glacier, East Nunatak Glacier, West Nunatak Glacier,
Mountains:Mount Armour, Mount Aylesworth, Mount Duff, Mount Herbert, Mount Wade,